[sdiy] Most popular DIY modular format?

[Andre Majorel]

On 2006-04-14 18:44 -0700, Nicholas Gregorich wrote:

> I am particularly interested in Frac versus Euro for myself
> (space) but I am still interested in what everyone is using for
> their DIY projects.
> 
> Which format has the most available 3rd party modules, or maybe
> the greatest variety?  Is there anything inherently
> easier/harder about building modules for any particular format?

One drawback of eurorack is the waste of vertical space. The outer
height is 3U (133 mm) but due to the mounting rails, the maximum
PCB height is barely 112 mm. You probably don't want to use 24 mm
pots on a eurorack panel.

As frac rack mounting rails do not have a "lip" above and below
the panel they're potentially more compact. However, since the
rails are "recessed" (http://blacet.com/misc.html), it seems the
maximum PCB height is actually a bit less than it is with the
eurorack format. http://blacet.com/tech.html says 4.22", about
4.5 mm shorter than eurorack. From what I've seen, PCB makers go
for 111 mm.

Frac rack cases are cheap and the rails can be DIYed (U-shaped
sheet metal). Eurorack cases are relatively expensive and hard to
DIY because the rails are made from aluminium profile. However,
you can buy just the rails and tapped strips (or square nuts) from
Radiospares.

The eurorack format is very common in industrial equipment (at
least where I live). You can find cheap eurorack cases through
surplus stores and skip diving.

-- 
André Majorel <amajorel at teaser.fr>
http://www.teaser.fr/~amajorel/